| 摘要 |
PROBLEM TO BE SOLVED: To provide a zoom lens which has a wide angle of view, a high zoom ratio, and high optical performance over the entire zoom range, and whose entire system is compact.SOLUTION: The zoom lens comprises, in order from an object side to an image side: a first lens group having positive refractive power; a second lens group having negative refractive power; a third lens group having positive refractive power; and a fourth lens group having positive refractive power, and during zooming from a wide angle end to a telephoto end, the first lens group moves along a locus convex toward the image side, and the third lens group moves toward the object side. The first lens group comprises, in order from the object side to the image side: a first lens having negative refractive power; a second lens having positive refractive power; and a third lens having positive refractive power. The distance dbetween the first lens and the second lens, the focal length fw of the entire system at the wide angle end, and the smallest refractive index Np among the refractive indices of the materials of the positive lenses included in the first lens group, are appropriately set, respectively. |
